it is important to realize that around 50 percent of the SP500′s earnings are generated overseas

Total profits for the constituents of the S&P 500 index are of the order of $1.1 to $1.12 trillion in this past year (not all have reported yet so difficult to be exact). And if 50% of them are overseas profits then that's $600 billion or so.

Or, when we put it into the context of US GDP, that's about four percentage points of GDP.

Taking that off the 11% of GDP that is US corporate profits leaves us with 7%, or much more like the long run average.

The rise in GDP of corporate profits has at least something to do with the increased globalisation of the economy rather more than it does with the oppression of the workers by capital. As so often, the devil is in the details of the measurement.

One such detailed point: we could assume that foreigners must also be making profits in the US and therefore there's 3 or 4% of GDP being paid out again to foreigners. But that's not actually quite how they measure it, there's an asymmetry here. Corporate profits are measured from Federal income tax returns: companies who have invested in the US will be reporting their US profits on such forms. As will US corporations who have made foreign profits. Thus this measure includes the corporate profits made in the US by foreigners as well as the foreign profits made by US companies.